Standard Model Higgs Searches at the LHC

The search for the Higgs boson, a key component in the Standard Model description of electroweak symmetry breaking, is a major goal of the physics program at the Large Hadron Collider (LHC) at CERN. Both ATLAS and CMS, experimental collaborations at LHC, have done extensive simulation and performance studies to optimize their strategies for this search. Some of these studies are discussed, as well as the resulting discovery potential (as a function of the Higgs boson mass), for the main experimental signatures that will be addressed by the two collaborations

Analyses of high mass resonances at ATLAS and CMS

Several plausible extensions of the Standard Model predict the existence of high mass resonances that can be reconstructed (either fully or partially) in the ATLAS and CMS detectors using leptons, jets and the missing transverse energy. We present the results of recent detailed studies of these searches performed by both collaborations, focusing on the potential for discovery and limits setting with an integrated luminosity of the order of 200/pb per experiment

Incorporation of biosynthesized silver nanoparticles in active biodegradable films of potato starch

En este trabajo se presenta el estudio del efecto de la incorporación de nanopartículas de plata biosintetizadas sobre las propiedades de películas biodegradables fabricadas a partir de almidón de papa y comprobar su potencial para ser usado como material activo. Las nanopartículas de plata fueron fabricadas mediante ruta verde a partir de residuos de uva y fueron añadidas en el proceso de gelatinización de las películas en concentraciones de 3% y 6% v/v. Las nanopartículas de plata fueron caracterizadas mediante espectroscopía UV-Vis y FTIR, mientras que las películas fabricas fueron caracterizadas mediante su densidad y % de contenido de humedad. Las propiedades activas se caracterizaron usando cinética de absorción de agua y biodegradación por enterramiento en suelo. Se confirmó la integración de las nanopartículas de plata en películas biodegradables fabricadas a partir de almidón de papa confirmando los efectos en sus características físicas y propiedades activas en función del porcentaje de AgNp, las cuales pueden ser aprovechadas para la fabricación de materiales activos

Aperture effects on the oxygen abundance determinations from CALIFA data

This paper aims at providing aperture corrections for emission lines in a sample of spiral galaxies from the Calar Alto Legacy Integral Field Area Survey (CALIFA) database. In particular, we explore the behavior of the log([OIII]5007/Hbeta)/([NII]6583/Halpha) (O3N2) and log[NII]6583/Halpha (N2) flux ratios since they are closely connected to different empirical calibrations of the oxygen abundances in star forming galaxies. We compute median growth curves of Halpha, Halpha/Hbeta, O3N2 and N2 up to 2.5R_50 and 1.5 disk R_eff. The growth curves simulate the effect of observing galaxies through apertures of varying radii. The median growth curve of the Halpha/Hbeta ratio monotonically decreases from the center towards larger radii, showing for small apertures a maximum value of ~10% larger than the integrated one. The median growth curve of N2 shows a similar behavior, decreasing from the center towards larger radii. No strong dependence is seen with the inclination, morphological type and stellar mass for these growth curves. Finally, the median growth curve of O3N2 increases monotonically with radius. However, at small radii it shows systematically higher values for galaxies of earlier morphological types and for high stellar mass galaxies. Applying our aperture corrections to a sample of galaxies from the SDSS survey at 0.02<=z<=0.3 shows that the average difference between fiber-based and aperture corrected oxygen abundances, for different galaxy stellar mass and redshift ranges, reaches typically to ~11%, depending on the abundance calibration used. This average difference is found to be systematically biased, though still within the typical uncertainties of oxygen abundances derived from empirical calibrations. Caution must be exercised when using observations of galaxies for small radii (e.g. below 0.5R_eff) given the high dispersion shown around the median growth curves.Comment: Accepted for publication in Ap

The Large Aperture GRB Observatory

The Large Aperture GRB Observatory (LAGO) is aiming at the detection of the high energy (around 100 GeV) component of Gamma Ray Bursts, using the single particle technique in arrays of Water Cherenkov Detectors (WCD) in high mountain sites (Chacaltaya, Bolivia, 5300 m a.s.l., Pico Espejo, Venezuela, 4750 m a.s.l., Sierra Negra, Mexico, 4650 m a.s.l). WCD at high altitude offer a unique possibility of detecting low gamma fluxes in the 10 GeV - 1 TeV range. The status of the Observatory and data collected from 2007 to date will be presented.Comment: 4 pages, proceeding of 31st ICRC 200

Water Cherenkov Detectors response to a Gamma Ray Burst in the Large Aperture GRB Observatory

In order to characterise the behaviour of Water Cherenkov Detectors (WCD) under a sudden increase of 1 GeV - 1 TeV background photons from a Gamma Ray Burst (GRB), simulations were conducted and compared to data acquired by the WCD of the Large Aperture GRB Observatory (LAGO). The LAGO operates arrays of WCD at high altitude to detect GRBs using the single particle technique. The LAGO sensitivity to GRBs is derived from the reported simulations of the gamma initiated particle showers in the atmosphere and the WCD response to secondaries.Comment: 5 pages, proceeding of the 31st ICRC 200